[sesqu]

Note that the batteries do not store 350 W/kg, but 350 Wh/kg. That means the majority of weight is batteries, since you need 1 kg/kW for the day but 1 kg/kW + 12 h * 1 kg / 350 Wh for the night, giving a total of 36.3 kg/kW of continuous power. The article implied that these things could not store enough power for the nighttime, which is easy to believe from those numbers.

An RTG at 2 kg/kW would be so ridiculously good value that it makes you wonder what has changed about aviation drones to make this viable only now. Is it really just the radiation thing?